The existence of single wall magnetic domains in certain materials under particular conditions is described in many prior art publications and patents, and these are usually referred to as magnetic bubble assemblies. Most of the magnetic bubble data storage systems of the prior art are two-dimensional, that is, essentially planar. However, it is generally understood that three-dimensional data storage is more economical and more efficient and faster to access than the planar type. U.S. Pat. No. 3,983,547, for example, describes a three-dimensional magnetic bubble memory which may be used for data storage.
The prior art magnetic bubble devices usually require an in-plane rotating magnetic field for purposes of magnetic bubble propagation. The magnetic field acting in a thin patterned permalloy layer creates magnetic poles causing the magnetic bubbles to propagate in preferred directions as determined by the pattern. The rotating magnetic field in such arrangements is effective in the thin layer in which the permalloy lies. Such magnetic bubble devices may be made three-dimensional, to increase the data density without increasing the equipment necessary for generating the rotating magnetic field.
The prime objective of the assembly and system of the present invention is to provide a data storage and retrieval system, and the like, which includes a magnetic bubble memory for storing binary data which is preferably three-dimensional, and in which data retrieval is achieved by directing one or more laser beams through the memory onto corresponding photo-voltaic generator/detectors so that rapid data retrieval may be achieved.
Another object of the invention is to provide such an improved data storage and retrieval system which in addition to providing data retrieval on a rapid time basis is relatively economical and simple to construct, and which exhibits relatively small space requirements as compared with prior art data storage and retrieval systems.